INMP521: Ultra-Low Noise Microphone with Bottom Port and PDM Digital Output


InvenSense MEMS Microphone

The INMP521 is a high performance, ultra low noise, low power, digital output bottom-ported omnidirectional MEMS microphone. The INMP521 consists of a MEMS microphone element and an impedance converter amplifier followed by a fourth-order Σ-Δ modulator. The digital interface allows for the pulse density modulated (PDM) output of two microphones to be time-multiplexed on a single data line using a single clock. The INMP521 is function- and pin-compatible with the INMP421 microphone, providing an easy upgrade path.

The INMP521 has a very high SNR and common sensitivity of −26 dBFS, making it an excellent choice for far field applications. The INMP521 has an extended wideband frequency response resulting in natural sound with high intelligibility. Low current consumption and a sleep mode with less than 1 µA current consumption enables long battery life for portable applications. The INMP521 complies with the TIA-920 Telecommunications Telephone Terminal Equipment Transmission Requirements for Wideband Digital Wireline Telephones standard. The INMP521 is available in a thin 3 mm × 4 mm × 1 mm surface-mount package. It is reflow solder compatible with no sensitivity degradation. The INMP521 is halide free.

† – 7” Tape and reel to be discontinued. Contact for availability.

INMP521 Functional Block Diagram

INMP521 Functional Block Diagram


  • Smartphones and feature phones
  • Tablet computers
  • Teleconferencing systems
  • Digital still and video cameras
  • Bluetooth headsets
  • Notebook PCs
  • Security and surveillance

Features and Benefits

  • Small and thin 3 mm × 4 mm × 1 mm surface-mount package
  • Omnidirectional response
  • Very High SNR of 65 dBA
  • Sensitivity of −26 dBFS
  • Extended frequency response from 100 Hz to 16 kHz Low current consumption: 900 µA
  • Sleep mode for extended battery life, <1 µA consumption
  • 120 dB maximum SPL
  • High PSR of -80 dBFS
  • Fourth-order Σ-Δ modulator
  • Digital PDM output
  • Compatible with Sn/Pb and Pb-free solder processes
  • RoHS/WEEE compliant


Application Notes (General)

Application Notes (Specific)

Evaluation Board User Guides


Part # Output Port Location SNR Equivalent
Input Noise
Frequency Response
Maximum SPL Sensitivity @1kHz Sensitivity Tol Package Size Documentation Flex Board Evaluation Board Device
UNITS: (dBA) (dBA) (min - max) +/- dB mm (.pdf) (add to cart) (add to cart) (add to cart)

PDM Bottom 65dB 29dB 100Hz - 16kHz 120dB SPL -26 dBFS 3dB 3.00x4.00x1.00 Datasheet

  • Disclaimer

    • InvenSense sensors should not be used or sold in the development, storing, production and utilization of any conventional or mass-destructive weapons or any other weapons or life-threatening applications as well as in any other life-critical applications including but not limited to medical equipment, transportation, aerospace and nuclear instruments, undersea equipment, power plant equipment, disaster prevention and crime prevention equipment. In devices or systems whereby malfunction of these products can be expected to result in personal injury and casualties, InvenSense customers using or selling these products do so at their own risk and agree to keep InvenSense harmless from any consequences. InvenSense reserves the right to make changes to this product, including its circuits and software, in order to improve its design and/or performance, without prior notice.

      InvenSense makes no warranty, either expressed or implied with respect to any product, and specifically disclaims all other warranties, including warranties for merchantability, non-infringement, and fitness for any particular purpose. For more information go to Terms and Conditions.

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